Guys,
One tool short in my garage is an impact........ I know I know. I really want one. I bought a new CS 130 alternator and I need to change the serp pulley to my V-belt pully I currently have. I can not for the life of me get that nut to back off. I've got a 3/8 wratchet with an allen in the shaft and then a 2 foot wrench on the nut. I've beat on it........ nothing. These are standard threads correct. I'm going to shot myself if these are left handed threads.

Randy,
The threads are "normal" right hand threads. If they were left hand they would tend to loosen as the belt turned the pulley I have absolutely never been able to get them loose without using the impact.

DO you have a any friends at an auto repair shop that could bust it loose for you ?

What Bill said. I got an alternator from Autozone and they swapped the pulley with the one on my core. They used a battery powered impact that they kept in their toolbox behind the counter. You have to shock it off there.

borrowed an 18 Volt Snap-On impact from a friend. Good Lord that was easy. Held the pully with my leather glove (not even sure if I needed to hold the fan). Whack, Whack, Whack........ old pulleys off, swapped and back in. 2 minutes tops. I need to get me one of those!!!

I usually get down on the floor and wrestle with em! Use the longest allen wrench you can find, and set it so it is against the floor, and lay into the other wrench with your body weight. Then go to doctor to find out what all the sore parts are. I got real lucky recently; got 3 of them off without hurting myself....and I own an impact. I'm so used to doing things without the proper tools, I forget I have them sometimes!!

I bought the CS130 for a Pontiac Safari Wagon and it had the V-belt pulley.
Maybe take it back for that one ?

as noted here

"Another good 105 Amp CS130 donor vehicle is the 1989 Pontiac Safari Wagon 5.0L. This one saves you the pulley swap as it comes with a v-pulley. 6 and 12 o'clock mounts; bolted right up on the '69. P/N P79223"

If you have a vise.....with soft jaws installed, you can take the alternator apart, watch the clocking.... put the shaft in the vise and unscrew the nut.Use toothpicks to hold the brushes back when you put it back together, and don't forget to remove the toothpicks !!!!!. And yes I have left the toothpicks in.